Periodic fluctuations
[经] 周期性波动
🧩 词语组成解析
periodic
[,pɪrɪ'ɑdɪk]
adj. 周期的;定期的;回归的;间歇的，时而发生的;
n. 起伏现象；变动；波动（fluctuation的复数）
🗣️ 情景例句
What was that?
你说什么？
How much is the rent for a month?
每月租金多少？
Now, this is the chemistry lab. Have you been in this lab before?
好啦，这是化学实验室。你们以前到过这个实验室吗？